Connecting plate for battery holder and method of producing the same

ABSTRACT

The connecting plates ( 10, 10′ ) for a battery holder are characterized in that a molded resin plate ( 11 ) for integrally molding bus bars ( 16, 16′ ) for connecting a plurality of batteries (A) at intervals corresponding to an arrangement of the plurality of batteries incorporates voltage detection terminals ( 17 ) for detecting voltages of the desired batteries in such a condition as to be connected to the bus bars.

BACKGROUND OF THE INVENTION

The present invention relates to connecting plates mounted in a batteryholder for containing a number of columnar batteries for use in anelectric vehicle or the like and to a method of producing the same.

The present application is based on Japanese Patent Application No. Hei.9-279257, which is incorporated herein by reference.

As a member for connecting plural batteries in series or in parallel,conventionally, a connecting plate 100 shown in FIGS. 25(A) and 25(B) isproposed.

The connecting plate 100 comprises a molded resin board 103 and bus bars102 which are integrally molded with a resin. The bus bars 102respectively connect to two batteries 101. In a molded resin board 103of the connecting plate, a hexagonal window 103 a and a rectangularwindow 103 b through which electrode holes 102 a at the ends of thebatteries 101 are exposed are formed. The two batteries 101 areconnected to each other by fastening the bus bars 102 respectively tonut-shaped positive and negative electrodes 101 a and 101 b by bolts104. Also a ring terminal 105 partially constituting a voltage detectioncircuit is connected to one of the windows or the hexagonal window 103a. A fuse case 107 is connected in series to the other end side of anelectric wire 106 which is connected at one end to the ring terminal105. The other end of the electric wire is connected to an ECU which isnot shown. A fuse 108 is housed in the fuse case 107. The ends of thefuse are connected to electrical contact portions 109 a of femaleterminals 109 connected to the electric wire 106, respectively.

FIG. 26 shows another example of a connecting plate of the prior art.

In the connecting plate 100′, plural L-shape bus bars 102′ respectivelyhaving connecting legs 102 b′of different lengths are moldingly fixed bya molded resin board 103. One end of each of the connecting legs 102 b′protrudes from one side edge of the molded resin board 103. Ends on oneside of electric wires 106 are welded to the protruding ends,respectively. The other ends of the wires are connected via a fuse case107′ to an ECU which is not shown.

In the fuse case 108′, two L-shape pressure contact terminals 111 areopposingly disposed on a case substrate 110. The electric wires 106 arewelded to basal plates 111 a of the pressure contact terminals 111,respectively. Lead wires 108 a′ of fuses 108 are connected by pressurecontact to slots 111 c of pressure contact pieces 11 b upstanding fromthe basal plates 111 a, respectively.

The connecting plate 100 of FIG. 25 has many connecting portions in onecircuit. In the voltage detection circuit, for example, there are sixconnecting portions indicated by letters a, b, . . . , and f. The numberof parts is large. Therefore, there is a fear that the reliability ofelectrical connection is impaired. Furthermore, a work of fasteningbolts must be conducted while holding respective ring terminals 105 oneby one by a hand. As the number of electric wires to be connected islarger, therefore, the works of laying and routing the electric wiresbecome more cumbersome and difficult.

By contrast, in the connecting plate 100′ of FIG. 26, the L-shape busbars 102′ of different dimensions are used. Therefore, the plate hasdifficulties in cost and production management. In the same manner asthe connecting plate 100, the number of parts is large and there aremany connecting portions in one circuit (five portions a′, b′, . . . ,e′). Moreover, the connecting plate has a problem in that the weldingportions between the electric wires 106 and the connecting legs 102 b′must be protected.

Furthermore, the electric wires 106 for the connecting plates 100 and100′ are directly connected to the batteries 101, and therefore anadequate protecting structure may be required. However, such protectingstructure is complicated since bulky members such as the fuse cases 107and 108′ are attached to the electric wires 106.

FIG. 27 shows a structure in which batteries for an electric vehicle orthe like are directly connected to one another without using connectingplates. In each of rectangular batteries 101′, the positive and negativeelectrodes 101 a′ and 101 b′ are juxtaposed in one end side. Adjacentbatteries are connected to each other by a main-power source wire 112.An electric wire 106 (a voltage detection circuit) which has a fuse case107 in the same manner as FIG. 25 is connected to a required electrode101 b′.

Also in this case, in the same manner as described above, the number ofparts is large (the voltage detection circuit). Since the electric wireshave many exposed portions, it is dangerous. Furthermore, the main powersource wire 112 and the electric wire 106 of the voltage detectioncircuit intersect with each other, so that the wiring is complicated.This often causes the wiring to be erroneously conducted.

In the cases of the connecting plates 100, 100′, it may be reasoned toform the connecting electric wire 106 in the molded resin plate 103 byinsert molding.

However, a group of electric wires 113 are rigidly secured within amolded resin plate 114 but set free outside by the conventional insertmolding as shown in FIG. 28 and this allows stress to be concentrated inthe root portion 113 a of the electric wires 113 as the boundaryportion. In an extreme case, slight external force acting on the rootportion 113 a may result in rupture that portion. In order to preventthis situation, the group of electric wires 113 may be bound with a band115 for fixing purposes or fixed by providing fixing means in part of oron the periphery of the molded resin plate 114. Even in this case, suchwork is done after the insert molding operation and it is impossible toeliminate the concentration of stress in the root portion 113 a.

Moreover, one of the factors causing such a rupture to the root portion113 a of the electric wire 113 is biting in an electric-wire mountinggrooves 117 in the exit portion between the top and bottom forces.

In the conventional insert molding of electric wire, molten resin forcedinto a mold 114 from the nozzle 119 of a molding machine 118 is higherin heat-resistant temperature than the insulating cover of the ordinaryelectric wire 113 as shown in FIG. 29, which results in raising costbecause a heat-resistant electric wire such as what is covered withpolyimide resin has to be used.

SUMMARY OF THE INVENTION

It is an object of the present invention made in view of the foregoingproblems to provide a connecting plate for a battery holder and a methodof producing the connecting plate in which battery-to-battery connectingbus bars and voltage detection terminals forming voltage detectioncircuits are resin-molded integrally by insert molding to decrease thenumber of parts exposed outside so that an easy-to-fabricate, safetystructure is provided.

It is an another object of the present invention to provide a connectingplate for a battery holder, which connecting plate has a smaller numberof component parts and connections and offers excellent reliability ofelectrical connections and is unlikely to produce errors inbattery-to-battery connection and wiring.

It is still another object of the present invention to provide aconnecting plate so structured as to prevent stress from beingconcentrated in a portion where resin-molded connecting electric wiresby insert molding are drawn outside.

A further object of the present invention is to provide a method ofproducing a low-cost connecting plate capable of using ordinary electricwires covered with polyvinyl chloride or polyethylene in place ofspecial heat-resistant electric wires covered with polyimide resin.

Other and further objects of the invention will appear more fully fromthe following description.

In order to accomplish the aforesaid objects, a connecting plate for abattery holder according to the present invention is characterized inthat a molded resin plate for integrally molding bus bars for connectinga plurality of batteries at intervals corresponding to an arrangement ofthe plurality of batteries incorporates voltage detection terminals fordetecting voltages of the desired batteries in such a condition as to beconnected to the bus bars.

According to the present invention, a connecting plate for a batteryholder of an easy-to-fabricate, safety structure is obtainable whereinthe battery-to-battery connecting bus bars and the voltage detectionterminals forming voltage detection circuits are resin-molded integrallyby insert molding so as to decrease the number of parts exposed outside.

The voltage detection terminal has a superposed contact portion at oneend with respect to the bus bar, an electric-wire connecting portion atthe other and an device mounting portion for mounting a circuitprotective element between one and the other ends thereof; the other endof the electric wire whose one end is connected to the electric-wireconnecting portion is led out from the molded resin plate; and thecircuit protective element is connected to the device mounting portion.

With this arrangement, the bus bars and the voltage detection terminalare integrally and fixedly connected by insert molding and theconnecting electric wire with respect to the voltage detection terminalis sealed up in the molded resin plate, whereby it is possible toprovide such a connecting plate for a battery holder as has a smallernumber of component parts and connections and offers excellentreliability of electrical connections and is unlikely to produce errorsin battery-to-battery connection and wiring.

The molded resin plate according to the present invention is preferablyprovided with an electric wire holder integrally formed with one sideedge of the molded resin plate; and the other end side of the electricwire whose one end is connected to the voltage detection terminal isheld by the electric wire holder. Thus, a number of electric wiresconstituting the connecting plate for a battery holder are bundled andheld on one side edge, so that the electric wires are readily connectedto any other electrical equipment.

The molded resin plate according to the present invention is preferablyprovided with a pair of upper and lower elastic mats integrally moldedto one side edge of the molded resin plate; and the other end side ofthe electric wire whose one end is connected to the voltage detectionterminal is held by the mats.

According to the present invention, the stress applied to the roots ofthe group of electric wires drawn outside from the molded resin plate isabsorbed and eased by the mats comprising the upper and lower elasticbodies, whereby the electric wires are prevented from being ruptured.

In the device according to the present invention, the molded resin platehas a non-filling portion (a mounting window) vertically opened so thatthe device mounting portion of the voltage detection terminal is exposedfrom the connecting plate; and the voltage detection terminal iscontained in the non-filling portion.

Consequently, the connecting plate can be replaced from the outside whenthe circuit protective element is cut by fusing and maintenance isfacilitated.

The device mounting portion of the voltage detection terminal accordingto the present invention has a connecting piece for integrally holdingthe superposed contact portion and the electric-wire connecting portion;and the connecting piece is cut off in the non-filling portion, thecircuit protective element being connected between both ends of theconnecting piece.

According to the present invention, a great deal of cost reduction canbe anticipated as the number of component parts and that of man-hoursare small since the voltage detection terminal can be handled as onepart to which the circuit protective element is connected until theconnecting piece is cut off.

According to the present invention, window frames for mounting circuitprotective elements are preferably formed by providing a wallsurrounding the non-filling portion of the molded resin plate; and apair of element fixing arms corresponding to the window frames areprovided.

For example, the circuit protective element is temporarily fixed untilit is fixed by soldering with a pair of element fixing arms and this isconvenient for storage and transportation and when the circuitprotective element is fixed by soldering, it is prevented from droppingout even though the molded resin plate is turned upside down. Thesoldering work is thus facilitated.

A method, according to the present invention, of producing a connectingplate for a battery holder comprises the steps of:

a) preparing terminal-equipped electric wires by connecting the voltagedetection terminal to one end of each of a plurality of electric wiresinvariable or different in length;

b) arranging the voltage detection terminals of the plurality ofterminal-equipped electric wires in conformity with the arrangingpositions of to be superposed and connected bus bars, wiring a group ofelectric wires connected to the respective voltage detection terminalsso as to be drawn from one side edge of the molded resin plate andbinding the electric wires to form a plate harness;

c) preparing a primary molded piece by setting the plate harness thusformed to a primary mold and integrally resin-molding the plate harnessexcluding the superposed contact portion of the voltage detectionterminal;

d) preparing a secondary molded piece by setting the primary moldedpiece to a second mold, superposing the superposed contact portion ofthe voltage detection terminal properly on the battery-electrodeconnecting hole of the bus bars and integrally resin-molding thesuperposed combination; and

e)cutting the connecting piece of the device mounting portion where theprimary molded piece is exposed so as to connect the circuit protectiveelement between both ends of the connecting piece.

Since the bus bars, voltage detection terminals, connecting electricwires and the like are formed by insert molding through two steps;namely, the primary molding with respect to the plate harness and thesecond molding including the superposed connection of the bus bar andthe voltage detection terminal, dimensional control over the shrinkageof molded resin plate can readily be effected.

The step of preparing the primary molded piece preferably furthercomprises, according to the present invention, molding the direction inwhich the molten resin is supplied to the primary mold along a directionof wiring the electric wires of the plate harness set in the primarymold.

As a resin skin layer is initially formed on the surface of the electricwire and then high-temperature is thus prevented from being directlybrought into contact with the electric wire, it is possible to eliminatethe destruction of the electric-wire covering portion by fusing, whichresults in dispensing with the use of special heat-resistant electricwires covered with polyimide resin as before, thus making cost reductionfeasible.

It is also preferred to make the step of preparing the primary moldedpiece further comprise, according to the present invention, molding anexposed portion in part of the electric wire of the plate harness set inthe primary mold.

According to the present invention, dimensional control over the wholeconnecting plate is facilitated since the partial exposed portions ofelectric wires can be utilized for dimensional adjustment due toshrinkage of resin and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a battery holder having aconnecting plate for a battery holder which is an embodiment of theinvention;

FIG. 2 is a perspective view of the connecting plate for a batteryholder of FIG. 1;

FIG. 3 is an enlarged perspective view of main portions of theconnecting plate of FIG. 2;

FIG. 4 is an enlarged perspective view showing a connecting state of abus bar, a voltage detection terminal, and a circuit protecting devicewhich are shown in FIG. 3;

FIG. 5(A) is a circuit diagram showing connections of batteries andvoltage detection terminals in connecting plates 10 and 10′ of FIG. 1,and

FIG. 5(B) is a circuit diagram showing connections of PTC devices fordetecting heat generation in a battery;

FIG. 6 is a view illustrating a production step (pretreatment step) ofthe connecting plate for a battery holder of FIG. 1;

FIG. 7 is a view illustrating a production step (connection of terminalsand fitting to case) subsequent to that of FIG. 6;

FIG. 8 is a view illustrating a production step (a step of wiring aharness for a plate) subsequent to that of FIG. 7;

FIG. 9 is a view illustrating a production step (a primary molding)subsequent to that of FIG. 8;

FIG. 10 is a perspective view of main portions of a primary moldedproduct obtained in the step of FIG. 9;

FIG. 11 is a view illustrating a production step (a secondary molding)subsequent to that of FIG. 9;

FIG. 12 is a plan view showing a state in which the primary moldedproduct of FIG. 11 is set in a mold;

FIGS. 13(A) to 13(D) show the final production step (a step of mountinga circuit protecting device), and FIG. 13(A) is a plan view of a windowfor mounting a circuit protecting device, FIG. 13(B) is a perspectiveview of the window, FIG. 13(C) is a section view of the window, and FIG.13(D) is a section view showing a state in which the circuit protectingdevice is connected;

FIGS. 14(A) and 14(B) show a manner of leading out connecting wires ofthe connecting plate for a battery holder of FIG. 2, and FIG. 14(A) is aperspective view of main portions of a primary molded product P₁, andFIG. 14(B) is a perspective view of main portions of a secondary moldedproduct P₂;

FIGS. 15(A) to 15(B) show another embodiment of the primary molding stepof FIG. 9, and FIG. 15(A) is a perspective view of main portions ofupper and lower molds using a rubber mat, and FIG. 15(B) is an explodedperspective view of the main portions;

FIG. 16 is a section view showing another embodiment of the rubber mat;

FIGS. 17(A) and 17(B) show a supplementary embodiment of the primarymolding step of FIG. 9, and FIG. 17(A) is a perspective view of mainportions of an upper (lower) mold using another rubber mat, and FIG.17(B) is a section view of the main portions;

FIG. 18 shows an another supplementary embodiment of the primary moldingstep of FIG. 9 and is a view illustrating a method of supplying a resinto molds;

FIGS. 19(A) and 19(B) show main portions and illustrates a structure forconnecting the bus bar, the voltage detection terminal, and the circuitprotecting device in the connecting plate for a battery holder, and FIG.19(A) is a perspective view showing the secondary molding, and FIG.19(b) is a perspective view showing the final step;

FIG. 20(A) is a section view taken along the line X—X of FIG. 19(B), and

FIG. 20(B) is a section view taken along the line Y—Y of FIG. 19(B) andshowing a state in which the circuit protecting device is attached;

FIGS. 21(A) and 21(B) are views illustrating another structure forconnecting the bus bar, the voltage detection terminal, and the circuitprotecting device in the connecting plate for a battery holder;

FIGS. 22(A) and 22(B) show a structure for relaxing stress in thevoltage detection terminal of the connecting plate for a battery holderof FIG. 1, and FIG. 22(A) is a perspective view of main portions, andFIG. 22(B) is a section view taken along the line X—X of FIG. 22(A);

FIGS. 23(A) and 23(B) show another structure for relaxing stress in thevoltage detection terminal, and FIG. 23(A) is a perspective view of mainportions, and FIG. 23(B) is a longitudinal section view;

FIGS. 24(A) to 24(C) show a further structure for relaxing stress in thevoltage detection terminal, and FIG. 24(A) is a perspective view of avoltage detection terminal 17′, and FIGS. 24(B) and 24(C) arelongitudinal section views respectively showing states of attaching theterminal to window frames 14′ and 14″;

FIG. 25(A) is a perspective view showing main portions of an example ofa conventional connecting plate for a battery holder,

FIG. 25(B) is a longitudinal section view of a fuse holder shown in FIG.25(A);

FIG. 26 is a perspective view showing main portions of another exampleof a conventional connecting plate for a battery holder;

FIG. 27 is a view showing another example of conventional connectingbatteries;

FIG. 28(A) is a diagram illustrating a conventional structure for fixingelectric wires and a resin-molded plate together, and

FIG. 28(B) is a diagram illustrating a top and a bottom force; and

FIG. 29 is a diagram illustrating a method of supplying resin in aconventional mold.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the invention will now bedescribed with reference to FIGS. 1 to 24(c).

Referring to FIG. 1, A denotes a long cylindrical battery which is to beused in an electric vehicle or the like, and B denotes a battery holderfor housing a large number of batteries A. In each of the batteries A,nut-shaped positive and negative electrodes 2 a and 2 b having a femalethread are disposed at the ends of the body 1, respectively. A PTCdevice 3 is embraced by and fixed to the outer periphery of the body 1in order to check heat generation of the battery A.

The battery holder B comprises a rectangular frame-like main unit 4, andconnecting plates 10 and 10′ which are attached to the sides of the mainunit, respectively. In the illustrated example, the frame-like main unit4 has a frame structure in which plural support plates 6 where arearranged in parallel and in a row by using stays 7. In each of thesupport plates, eighteen battery insertion holes 5 in total are openedin a matrix of 6 holes in vertical and 3 holes in lateral. Plural bolts9 for fixing the battery holder to the vehicle body are implanted in oneside wall 8 extending in the longitudinal direction.

FIG. 2 is a perspective view of the connecting plate 10, FIG. 3 is anenlarged view of main portions of the plate, and FIG. 4 is a perspectiveview showing a connecting state of a bus bar, a voltage detectionterminal, and a circuit protecting device which are shown in FIG. 3.

The connecting plate 10 (10′) is configured by inserting and fixing busbars 16 and 16′ (see FIG. 12) connecting the plural batteries, voltagedetection terminals 17, fuses 21 serving as circuit protecting devices,connecting wires 22, and the like, into a molded resin board 11.

In the molded resin board 11, hexagonal windows 12 and rectangularwindows 12′ for connecting electrodes are formed in accordance with thearrangement of the plural batteries A. A rectangular window 13 forconnecting the PTC device is formed at the side of each of the windows12 and 12′. Two fuse mounting windows 14 are juxtaposed between desiredhexagonal and rectangular windows which are denoted by 12 ₁ and 12 ₁′.Connecting pieces 15 for connecting the PTC devices 3 in series areembedded between adjacent rectangular windows 13, and connecting endportions 15 a at the ends and having a connection hole 15 b are exposedthrough the rectangular windows 13. The fuses 21 are housed in the fusemounting windows 14, respectively.

Each of the bus bars 16 is formed as a link-like plate member throughwhich a large current can flow. A battery connection hole 16 a is formedat each end. The bus bars are arranged at intervals corresponding to thearrangement of the batteries A. The bus bars 16′ are formed into aU-like shape so as to connect adjacent batteries A in a vertical row.

Among the plural bus bars 16 (16′), for example, bus bars denoted by 16₁ are connected to the voltage detection terminals 17, respectively.

Each of the voltage detection terminals 17 (see FIG. 6) comprises anoverlap contact portion 18 opposed to the corresponding bus bar 16, adevice mounting portion 19 which is continuous to the overlap contactportion, and a wire connecting portion 20. These portions are integrallyformed by punching or bending an electrically conductive metal plate.

The overlap contact portion 18 is formed as a square or rectangularplate member of a size which enables the portion to be substantiallyoverlapped to an end portion of the bus bar 16. A bolt insertion hole 18a having the same diameter as the battery connection hole 16 a is formedin a center portion. Plural (in the illustrated example, four) resinleakage inspection holes 18 b of a small diameter are formed around thehole 18 a. Resin leakage preventing pieces 18 c and 18 c′ which servealso as positioning pieces are downwardly bent and formed in two edgesof the overlap contact portion 18 which perpendicularly intersect witheach other. When the pieces 18 c and 18 c′ abut against side edges ofthe end portion of the bus bar 16, the center of the bolt insertion hole18 a is automatically made coincident with that of the batteryconnection hole 16 a.

The device mounting portion 19 is continuously formed via a connectionpiece 18 d which is downward cranked, on the resin leakage preventingpiece 18 c′ which is on one of the two adjacent edges of the overlapcontact portion 18. The device mounting portion 19 includes a pair oflead connecting pieces 19 a opposed to leads 21 b of the ends of thefuse 21, and a connecting piece 19 b which integrally holds the twoconnecting pieces. A lead connection hole 19 c is formed in each of thelead connecting pieces 19 a. The device mounting portion 19 is madelower in level than the overlap contact portion 18 by the connectionpiece 18 d and one of the lead connecting pieces 19 a, and elongates inparallel with the resin leakage preventing piece 18 c′. The wireconnecting portion 20 is formed continuously with the other leadconnecting piece 19 a. One end of the insulated wire 22 is connected toa pair of a wire barrel 20 a and an insulation barrel 20 b of the wireconnecting portion 20, by crimping or the like. The other end side ofthe wire 22 is laid together with the other wires so as to be led out toone side edge 11 a of the molded resin board 11. The wires are held atthe side edge by a wire holder 23 so as to be arranged at givenintervals.

The device mounting portion 19 of the voltage detection terminal 17,i.e., the pair of the lead connecting pieces 19 a and the connectingpiece 19 b are exposed through the fuse mounting window 14 of the moldedresin board 11. A pair of fuse engaging arms 24 which have at the upperend a hook-like engaging projection 24 a are integrally formed on theinner walls 14 a (see FIG. 13) which are on both the sides of the windowand sandwich the connecting piece 19 b, respectively.

After insert molding of the molded resin board 11, the connecting piece19 b of the device mounting portion 19 is cut away in the fuse mountingwindow 14. The leads 21 b of the ends of the fuse 21 are respectivelypassed through the lead connection holes 19 c of the remaining leadconnecting pieces 19 a at both the sides, and then applied with solder25, whereby the fuse 21 is connected and fixed to the voltage detectionterminal 17. The fuse 21 the leads of which are passed through the leadconnection holes 19 c is clamped by the pair of fuse engaging arms 24,and the hook-like engaging projections 24 a, thereby preventing the fusefrom slipping off. Even when the molded resin board 11 is turned upsidedown, therefore, the fuse is prevented from falling off. Furthermore, asoldering work can be easily conducted.

FIG. 5 is a connection diagram in the case where the batteries A areconnected in series by using the connecting plates 10 and 10′, and FIG.5(A) shows a voltage detection circuit for the batteries and FIG. 5(B)shows a temperature detection circuit for the batteries.

Returning to FIG. 1, the batteries A are inserted into the batteryinsertion holes 5 of the battery holder B in such a manner that theirpositive and negative electrodes 2 a and 2 b are alternatively inverted.The connecting plates 10 and 10′ are set on the electrodes 2 a and 2 bprotruding from the ends of the holder B, and the ends of the bus bars16 (16′) are alternatively fastened and fixed to the positive andnegative electrodes 2 a or 2 b of the batteries A by the bolts 26.

As a result, as shown in FIG. 5(A), the batteries A1, A₂, A₃, . . . ,A_(n) are connected in series by the bus bars 16 (16′). The fuses 21 areconnected to ends of single-pole bus bars 16″ and double-pole bus bars16 via the voltage detection terminals 17. When the wires 22 areconnected to an ECU which is not shown, therefore, the voltages of allthe batteries A can be always monitored for each sets of two batteries.Batteries A generating an abnormal voltage can be rapidly replaced withother ones in the unit of two batteries.

As described above, the PTC devices 3 are attached to the batteries A₁,A₂, . . . , A_(n), respectively. The lead wires (not shown) of the bothsides of each PTC device are connected to the ends of the connectingpiece 15 in the connecting plate 10 (10′). Specifically, screws whichare not shown are fastened to the connection holes 15 b of theconnecting end portions 15 a at the ends. On the other hand, the leadwires of the PTC device 3 are led out from through paths 13 a formed inone side of the rectangular windows 13. The lead wires are fixed by thescrews.

As a result, as shown in FIG. 5(B), all the PTC devices 3 of thebatteries A₁, A₂, . . . , A_(n) are connected in series. When any one ofthe batteries abnormally generates heat, the resistance of the PTCdevice 3 corresponding to the battery is suddenly increased, and hencethe check circuit is opened.

In this way, the embodiment has a structure in which an abnormal voltageand abnormal heat generation of the batteries A in the batter holder Bare always monitored.

Next, a method of producing the connecting plate 10 (10′) will bedescribed with reference to FIGS. 6 to 13.

First, the insulated wires 22 which are to be connected to the voltagedetection terminals 17 of the connecting plate 10 are prepared. For theconvenience of maintenance and the like, preferably, different colors ormarkers such as a pattern, a stripe, or a symbol are applied to theinsulating coating of the wires 22. The wires are cut into apredetermined length and the coating at each end is peeled off.

Next, as shown in FIG. 6, the exposed core wire 22 a at one end isconnected to the wire connecting portion 20 of the voltage detectionterminal 17, and a female (or male) connector terminal 30 is connectedto the other end, thereby producing a terminal-equipped wire 22′.

As shown in FIG. 7, the connector terminals 30 of the thus preparedterminal-equipped wires 22′ are then inserted into and engaged with aterminal chamber (not shown) of a connector (housing) 31. The engagingstructure between the connector terminals and the terminal chamber maybe formed in accordance with known means, and hence its illustration isomitted.

Next, as shown in FIG. 8, the voltage detection terminals 17 of theterminal-equipped wires 22′ are arranged on a wiring table 32 inaccordance with the arrangement positions of the bus bars 16 (16′) towhich the terminal-equipped wires are connected to be overlapped. Thewires 22′ connected to the voltage detection terminals 17 are laid so asto be combined in a center portion of the molded resin board 11, inorder to lead out the wires from one side edge of the board. The wiresare combined into a flat shape by tapes 33 to form a harness 34 for aplate.

The above will be described in more specifically. In the battery holderB of FIG. 1, the number and positions of the battery insertion holes 5of the support plate 6 are predetermined, and hence also the layout ofthe bus bars 16 and 16′ in the connecting plate 10 is uniquelydetermined. In accordance with the layout, therefore, a pair ofconnector engaging pins 35, and plural pairs of wire engaging pins 36(36 ₁ to 36 ₃) and terminal engaging pins 37 (37 ₁ to 37 ₃) areretractably disposed on the wiring table 32.

These pins 35, 36, and 37 erect from a mounting base which is not shown,and are caused to collectively protrude from and retract into holesformed in the wiring table 32 by raising and lowering the mounting base.

First, second, and third wire engaging pins 36 ₁, 36 ₂, and 36 ₃ whichare respectively paired are linearly arranged at the center of thewiring table 32 with starting from the side closer to the pair ofconnector engaging pins 35. The terminal engaging pins 37 ₁ to 37 ₃ arearranged so as to sandwich or on both the sides of the pairs of wireengaging pins 36 ₁ to 36 ₃. The gap between the engaging pins 36 ₃ whichare remotest from the connector engaging pins 35 is smallest. As a pairof pins are closer to the connector engaging pins 35, the gap betweenthe pins is larger. These gaps respectively form spans in which thewires 22′ laid in the gap can be housed in a substantially flat manner.

In the formation of the harness 34 for a plate, the terminal-equippedwires 22′ (see FIG. 7) which are previously obtained are moved onto thewiring table 32, the back face (the wire connection side) of theconnector 31 abuts against the pair of connector engaging pins 35, andthe wires 22′ are then arranged between the wire engaging pins 36 ₁,between the pins 36 ₂, and between the pins 36 ₃.

Next, the plural wires 22′ between the wire engaging pins 36 ₃ arearranged so that a flat state in which the wires do not overlap norcross with one another is maintained. The wires are bent at the pins 36₃ to either side into an L-like shape. The bolt insertion holes 18 a ofthe overlap contact portions 18 in the voltage detection terminals 17 atthe tip end portions of the wires are engaged with the terminal engagingpins 37 ₃, respectively. Thereafter, the flat portions of the wires 22′are bundled by the tape 33. Also the wires 22′ between the wire engagingpins 36 ₂ and between the pins 36 ₁ are then processed in the samemanner.

As a result, as shown in FIG. 8, the harness 34 for a plate is formed inwhich the connector 31 is attached to the one-end side of the flatlyarranged wires 22′, the other-end sides are branched at given intervalsby bending into an L-like shape in a bilaterally symmetrical manner bythe wire engaging pins 36 and the terminal engaging pins 37, and thevoltage detection terminals 17 are connected to the tip ends.

The harness 34 for a plate is detached from the wiring table 32, and, asshown in FIG. 9, then set in a recess 39 of a primary mold 38 to besubjected to the insert molding by a known method (the upper moldcorresponding to the mold 38 is not shown), thereby obtaining a primarymolded product P₁ shown in FIG. 10.

In the connecting plate 10 of FIG. 2, the dimension X between the outervoltage detection terminals 17 _(o) which are largely separated fromeach other, the dimension Y between the inner terminals 17 _(i), and thedimension Z between the terminals 17 _(o) which are vertically separatedfrom each other must be correct, and hence severe accuracy is requested.However, it is difficult to perform the insert molding by one stepwhile, from an initial stage, maintaining the accuracy of the dimensionsbetween the many bus bars 16 and 16′ and the wire-equipped voltagedetection terminals 17.

As apparent from FIG. 10, the primary molded product P₁ is integrallymolded by primary molded resin boards 11A, 11B, 11B′, 11C, and 11C′ withleaving a part 22A′ of the wires 22′, and the overlap contact portions18 and the device mounting portions 19 of the voltage detectionterminals 17.

Specifically, there exist the wire exposed portions 22A′ among theprimary molded resin board 11A in a center portion of the primary moldedproduct P₁, and the primary molded resin boards 11B, 11C, 11B′, and 11C′on the lateral sides. Furthermore, there is no tie in the gaps on thelateral sides between the primary molded resin boards 11B and 11C, and11B′ and 11C′ where the wires 22′ do not exist. The gaps constitute freeportions F.

In the primary molded resin board 11A in the center portion, plural pinholes 41 and vertical grooves 42 are formed, and the wire holder 23 isintegrally disposed. The pin holes 41 and the vertical grooves 42 areformed by pins and bosses (both are not shown) which protrude into therecess 39 in order to prevent the wires 22′ from, in the insert moldingusing the primary mold 38, being subjected to an excessive force due tothe injection force of the resin, or twined with each other. A wirefixing piece 43 which is indicated by phantom lines is disposed in themold 38, so that, in the primary insert molding, the wires 22′ on theside of the connector 31 are prevented from being disturbed and stressconcentration at the outlet of the wire holder 23 is prevented fromoccurring.

In the primary molded resin board 11B (11B′), a window frame 14′ forforming a resin non-filled portion, i.e., the fuse mounting window 14 isdisposed, two voltage detection terminals 17 _(o) and 17 _(i) are fixedby the insert molding so as to laterally interpose the window frame 14′therebetween, the overlap contact portions 18 of the two terminals areexposed to the outside, and the device mounting portions 19 are exposedin the window frame 14′.

By contrast, in the primary molded resin board 11C (11C′), laterallyarranged voltage detection terminals 17 _(o) and 17 _(i) which areconfigured in a similar manner as those of the primary molded resinboard 11B are vertically arranged, so that three or four terminals intotal are fixed by the insert molding.

Any one of the primary molded resin boards 11B 11C of the primary moldedproduct P₁ is configured by fixing two to four voltage detectionterminals 17 _(o) and 17 _(i) which are close to each other, by theinsert molding. Therefore, the terminals can be fixed with substantiallyhigh accuracy of the dimension between the terminals and without beinglargely affected by the kind of the resin.

In the primary molded product P₁, therefore, the dimensions X′, Y′, andZ′ between various terminals in FIG. 10 may be formed so as to be longerthan the dimensions of the connecting plate 10 of the final product ofFIG. 2, by using the wire exposed portions 22A′ and the free portions Fas dimension adjusting portions, and the dimensions may be finallyadjusted in the secondary molding.

Next, as shown in FIGS. 11 and 12, the primary molded product P₁ is setin a secondary mold 45, and a secondary insert molding is thenperformed.

In a recess 46 of the secondary mold 45, positioning engaging pins 47and 48 for the bus bars 16 and 16′ and the PTC device connecting pieces15 are disposed, and collar engaging pins 49 are disposed at the fourcorners. Moreover, the positioning bosses (not shown) for the pin holes41 and the vertical grooves 42 of the primary molded product P₁ aredisposed. The reference numeral 50 denotes a holder placing groove forthe wire holder 23.

The bus bars 16, 16′, and 16″, the connecting pieces 15, and a collar 51are correctly positioned and engaged by the various engaging pins 47 to49 in the recess 46. Thereafter, the primary molded resin boards 11A to11C, 11B′, and 11C′ of the primary molded product P₁ are set, and thepositioning of predetermined bus bars 16 and the voltage detectionterminals 17 is performed.

The positioning is performed in the following manner. The overlapcontact portions 18 of the voltage detection terminals 17 are overlaidon corner portions of the bus bars 16 and 16′ which have been set, sothat the resin leakage preventing pieces 18 c and 18 c′ of each of theportions abut against the side edges of the end portion of thecorresponding bus bar 16 or 16′ which perpendicularly intersect witheach other, as described above (see FIG. 4).

Next, an upper mold (not shown) which is paired with the secondary mold45 is set on the secondary mold, and the insert molding is thenperformed under predetermined conditions, thereby obtaining a secondarymolded product.

The secondary molded product is different from the completed connectingplate 10 shown in FIG. 2 in that the fuses 21 are not mounted to thefuse mounting windows 14. The illustration of the whole of the secondarymolded product is omitted.

Namely, in the secondary molded product, in the same manner as theconnecting plate 10, the bus bars 16 and 16′ and the like for connectingthe electrodes 2 a and 2 b of the batteries A, and the connecting pieces15 for connecting the PTC devices are embedded together with the primarymolded resin boards 11A to 11C and the like and the free portions F ofthe primary molded product P₁, into the molded resin board 11. Thehexagonal windows 12 and rectangular windows 12′ for connecting theelectrodes, and the rectangular windows 13 for connecting the PTCdevices are opened. The device mounting portions 19 of the voltagedetection terminals 17 are exposed through the fuse mounting windows 14.

When the fuses 21 are mounted to the fuse mounting windows 14 of thesecondary molded product, therefore, the connecting plate 10 which isthe completed product is obtained.

As shown in FIG. 13(A), in the secondary molded product P₂, the pair oflead connecting pieces 19 a of the device mounting portion 19 areconnected to each other by the connecting piece 19 b in the fusemounting window 14. As shown in FIG. 13(B), the connecting piece 19 b iscut away, the leads 21 a of the fuse 21 are passed through the leadconnection holes 19 c of the lead connecting pieces 19 a, and at thesame time the fuse body unit 21 a is pressingly inserted between thepair of fuse engaging arms 24.

As a result, as shown in FIG. 13(C), the fuse body unit 21 a is clampedbetween the engaging arms 24, and the hook-like engaging projections 24a serve as stoppers. Consequently, the fuse 21 does not vertically slipoff and is surely clamped.

Even when the secondary molded product P₂ is turned upside down as shownin FIG. 13(D), therefore, there arises no fear that the fuse 21 slipsoff, and the solder 25 can be applied very easily.

As a result of the above process, the connecting plate 10 (10′) which isthe completed product is obtained.

Since the fuse 21 is clamped by the pair of fuse engaging arms 24 so asto be prevented from slipping off, the secondary molded product P₂ canbe easily stocked and transported.

FIGS. 14(A) and 14(B) show other embodiments of the primary moldedproduct P₁ and the secondary molded product P₂ in which the manner ofleading out the connecting wires in the connecting plate is improved.

In the embodiment of FIG. 14(A), the primary molded resin board 11A inthe center portion of the primary molded product P₁ is configured sothat a fixing frame 51 is formed integrally with one side of the wireholder 23 for binding the wires 22′ and a band 115 (see FIG. 14(B)) forbinding the wires 22′ is tied to the fixing frame 51 so as to performthe fixation. According to this configuration, even when an externalforce acts on the wires 22′, stress concentration at the root portions22B of the wires can be relaxed or blocked.

During transportation or stock in the process of forming the primarymolded product P₁ into the secondary molded product P₂ shown in FIG.14(B), or after the secondary molding is performed and the moldedproduct is embedded into and protected by the molded resin board 11,therefore, the wires 22′ are effectively prevented from being broken.

FIGS. 15(A) and 15(B) show another embodiment for stress relaxation.

The primary molded product P₁ of FIG. 15(A) is configured so that, inplace of the wire holder 23 for bundling the wires 22′ of the primarymolded resin board 11A into a flat shape, a pair of upper and lower mats52 clamp the wires.

In each of the mats 52, plural wire placing grooves 52 b are arranged onone face of a block-like mat body 52 a. Each mat is made of an elasticmember having heat resistance, such as silicone rubber. The rear halfportions of the mats 52 which vertically clamp the wires 22′ areembedded into the primary molded resin board 11A, and the front halfportions protrude from the resin board 11A. Therefore, stress acting onthe root portions 22B of the wires 22′ can be absorbed and relaxed.

As shown in FIG. 15(B), a mat receive groove 53 is formed in the innerside of wire placing grooves 38 a of the primary mold 38, and the mats52 are placed in the mat receive groove. Therefore, the primary moldingmay be performed by a conventional method.

In the primary molding, the resin which is injected or filled into theprimary mold 38 is blocked by the upper and lower mats 52. Therefore,the interface portions (or edges) between the wire placing grooves 38 acan be loosely formed, so that the wires 22′ are prevented from beingbit.

FIG. 16 shows another embodiment of the mats for stress relaxation.

In mats 52′ shown in FIG. 16, a large number of projections 52 c areformed in a staggered manner on one face of each of mat bodies 52 a. Theprojections 52 c may have any one of shapes such as a cylindrical shape,a prism-like shape, and a semispherical shape. Preferably, theprojections have a semispherical shape.

The mats 52′ can be used in the primary molding by using the primarymold 38 having the mat receive groove 53 shown in FIG. 15(B), and attainthe same effects as that of FIG. 15(A).

FIGS. 17(A) and 17(B) show supplementary embodiments of the mats forstress relaxation and the primary mold.

Referring to FIG. 17(A), in each of upper and lower mats 52″, pluralwire placing grooves 52 b are disposed in one face of a mat body 52 a,and a pair of engaging bosses 52 d protrude from the opposite face ofthe mat body. The engaging bosses 52 d are provided at the tip end witha bulb-like engaging projections 52 d ₁.

In order to comply with the mats 52″, in a primary mold 38′, in place ofthe wire placing grooves 38 a, plural guide pins 54 are disposed so asto protrude in front and rear of a mat receive groove 53′, and engagingholes 55 corresponding to the engaging bosses 52 d of the mats 52″ aredisposed.

In the case of the mats 52″, when the engaging bosses 52 d are stronglypressed against the respective engaging holes 55, the engaging bosses 52d at the tip end pass through the engaging holes 55 to be engagedtherewith as shown in FIG. 17(B). Consequently, there is no fear thatthe mats 52″ which have been once set slip off. The wires 22′ may beplaced so as to separately or one by one pass through between the guidepins 54 which are arranged in front and rear of the mats 52″. As aresult, the wires naturally correspond in one to one relationship to thewire placing grooves 52 b of the mats 52″, and hence the work can besimplified.

FIG. 18 shows a method of supplying a resin to molds in the primarymolding.

Referring to FIG. 18, a resin filling hole 56 which is directed alongthe laying direction of the wires 22′ of the harness 34 for a plate (seeFIGS. 8 and 9) in the inner side is opened in a side face of the primarymold 38.

The flow of the molten resin injected from a nozzle 119 of a moldingmachine 118 is directed along the laying direction of the wires 22′ asindicated by the arrow lines. According to this configuration, a resinskin is first formed on the surfaces of the wires 22′, and hence the hotresin does not thereafter make direct contact with the wires 22′. As aresult, melt fracture of the wire coating portions is eliminated. Unlikethe prior art, therefore, it is not required to use a heat resistantmaterial such as a polyimide resin in the insulation coating of thewires 22 (22′).

FIGS. 19(A) and 19(B) are perspective views of main portions and showingthe structure for connecting the bus bar 16, the voltage detectionterminal 17, and the fuse 21. FIG. 19(A) shows a state in the secondarymolding, and FIG. 19(B) shows that in the final step. FIGS. 20(A) and20(B) are section views respectively taken along lines X—X and Y—Y ofFIG. 19(B). In order to simplify the drawings, the fuse engaging arms 24are not shown.

Prior to the secondary insert molding, the voltage detection terminal 17is positioned with respect to the bus bar 16. This positioning can beeasily performed because, as described above, the two resin leakagepreventing pieces 18 c and 18 c, which perpendicularly intersect witheach other serve as positioning pieces with respect to the bus bar 16.

In the secondary molding, a fear that a molten resin enters between theoverlapping faces of the bus bar 16 and the overlap contact portion 18is substantially eliminated by the blocking function due to the resinleakage preventing piece 18 c or 18 c′ which is positioned in the flowdirection of the molten resin. The bus bar and the portion are surelycontacted and fixed by mold fixation.

As shown in FIG. 20(A), even when a molten resin 57 enters between thebus bar 16 and the overlap contact portion 18, the entrance can beeasily checked through the resin leakage inspection holes 18 b, wherebya defective product and a failure in the flow can be prevented fromoccurring.

A secondary molded product P₂ which is checked that the resin leakagedoes not occur in the secondary insert molding is processed in thefollowing manner. In the fuse mounting window 14, the connecting piece19 b of the device mounting portion 19 is cut away as shown in FIG.19(B). The leads 21 a of the fuse 21 are passed through the leadconnection holes 19 c of the remaining lead connecting pieces 19 a atthe ends, and then applied with solder 25 as shown in FIG. 20(B).

As seen from the comparison of FIGS. 19(B) and 19(A), the leadconnecting pieces to which the leads 21 a at the ends of the fuse 21 areto be connected, i.e., the lead connecting piece 19 a on the side of theoverlap contact portion 18, and the lead connecting piece 19 a on theside of the wire connecting portion 20 are initially connected to eachother through the connecting piece 19 b. In the primary and secondarymoldings, therefore, the parts such as the overlap contact portion 18,the device mounting portion 19, and the wire connecting portion 20 canbe collectively handled as a single part, i.e., the voltage detectionterminal 17. As a result, the number of parts and the man-hour can bereduced, and the production cost can be lowered.

FIGS. 21(A) and 21(B) show other embodiments of the resin leakageinspection holes of the overlap contact portion, respectively.

The resin leakage inspection holes 18 b′ of FIG. 21(A) are formed asquadrant-like slits which are very larger in size than the resin leakageinspection holes 18 b. The four holes are symmetrically disposed aroundthe bolt insertion hole 18 a. The resin leakage inspection holes 18 b′are positioned diametrically outside a dish portion 26 a of the bolt 26.

In the embodiment shown in FIG. 21(B), the overlap contact portion 18′is formed into a doughnut-like disk shape, and the spaces between theround outer peripheral edge 18 e and the inner edge of the rectangularhole 12′ are used as resin leakage inspection holes 18 b″.

Both the resin leakage inspection holes 18′ and 18 b″ have an area whichis very larger than the area of the resin leakage inspection holes 18 b,and look like a window.

In the case where a large hole (or a window) such as the resin leakageinspection holes 18′ or 18 b″ is formed, when the molten resin injectedinto the molds in the insert molding reaches the inspection holes 18′ or18 b″, the resin is abruptly released and its pressure is lowered. Thisperfectly prevents the resin from entering toward the center portion(i.e., the bolt insertion hole 18 a), thereby eliminating a failure ofcontinuity between the bus bar 16 and the voltage detection terminal 17.

Returning to FIG. 20(B), in the connecting plate 10, the whole of theparts (the lead connecting pieces 19 a at the sides, the wire connectingportion 20, and the like) to which the fuse 21 is connected are bound bythe molded resin board 11. When an external force such as an impact or apressing force is applied to a part of the connecting plate 10,therefore, stress propagates via the resin board 11 to reach theconnection portions such as the solder 25, thereby producing a dangerthat a trouble such as a crack of the solder occurs.

FIG. 22 shows a structure for relaxing such stress. FIG. 22(A) is aperspective view of the fuse mounting window 14, and FIG. 22(B) is alongitudinal section view taken along the line X—X of FIG. 22(A).

Rectangular slits 58 are disposed around the whole periphery of thewindow frame 14′ of the primary molded resin board 11B (11C) in theprimary molded product P₁. The reference numeral 58 a denotes ties (inthe illustrated example, four ties) corresponding to spouts for a resinin the molding of the window frame 14′. A middle portion of each of thelead connecting pieces 19 a at the ends of the device mounting portion19 in the voltage detection terminal 17 is located in one of the slits58.

Even when an external force acts on the primary molded product P₁ (orthe secondary molded product P₂), therefore, stress due to the force isinterrupted by the slit 58, and the window frame 14′ and the internalparts such as the solder 25 are not affected by the stress.

Referring to FIG. 22(A), in order to eliminate the ties 58, the resinfilling hole (see FIG. 18) in the molds may be disposed for each of thewhole of the molds and the formation of the window frame. According tothis configuration, the window frame 14′ has a floating island of acertain kind which is supported by the lead connecting pieces 19 a atboth the sides, and hence the solder 25 inside the frame is perfectlyunaffected by the outside.

FIGS. 23(A) and 23(B) show another embodiment of the structure forrelaxing stress. FIG. 23(B) is a section view taken along the line X—Xof FIG. 23(A).

A window frame 14″ is pre-inserted aside from the primary molding (seeFIGS. 9 and 10) of the harness 34 for a plate.

The pre-insert may be previously prepared by using the voltage detectionterminal 17 having the device mounting portion 19. Therefore, theprimary molding (main insert) may be performed by using the window frame14″.

According to this configuration, an interface 59 is formed between theresin portion (the window frame 14″) of the pre-insert and that (theprimary molded resin board 11B, 11C) of the main insert. Even whenbending stress or the like is applied, therefore, a gap is formed in theportion and the propagation of the stress is suppressed. The resinmaterials of the pre-insert and the main insert may be identical with ordifferent from each other. From the view point of enhancement of thesuppression effect, it is preferable to use different materials.

FIGS. 24(A) to 24(C) show another embodiment of the structure forrelaxing stress. FIG. 24(A) is a perspective view of a voltage detectionterminal, FIG. 24(B) is a section view showing a state of attaching theterminal to the window frame 14′ of FIG. 22(A), and FIG. 24(C) is asection view showing a state of attaching the terminal to the windowframe 14″ of FIG. 22(B).

The voltage detection terminal 17′ shown in FIG. 24(A) is different fromthe voltage detection terminal 17 in that a second connection piece 18d′ which is upward cranked is disposed between the device mountingportion 19 and the wire connecting portion 20, and that, as a result ofthis disposition, the center axis of the wire connecting portion 20 isin a plane which is substantially flush with the overlap contact portion18.

As shown in FIG. 24(B), the bent portion serving as the secondconnection piece 18 d′ is located in the slit 58 in the outer peripheryof the window frame 14′. Alternatively, as shown in FIG. 24(C), the bentportion is located at the interface 59 between the window frame 14″ ofthe pre-insert and the primary molded resin board 11B and the like ofthe main insert.

In the case of FIG. 24(B), the existence of the slit 58 and the bentportion surely blocks the transmission of stress to the lead connectingpiece 19 a in the window frame 14′.

In the case of FIG. 24(C), the window frame 14″ of the pre-insert can bemoved (or slid) together with the fuse 21 inside the frame, and thisportion can similarly block the transmission of stress.

As set forth above, according to the present invention, the followingeffect is achievable.

A connecting plate for a battery holder of an easy-to-fabricate, safetystructure can be provided wherein the battery-to-battery connecting busbars and the voltage detection terminals forming voltage detectioncircuits are resin-molded integrally by insert molding so as to decreasethe number of parts exposed outside.

It is possible to provide such a connecting plate for a battery holderas has a smaller number of component parts and connections and offersexcellent reliability of electrical connections and is unlikely toproduce errors in battery-to-battery connection and wiring.

Furthermore, it is also possible to provide a connecting plate sostructured as to prevent stress from being concentrated in a portionwhere resin-molded connecting electric wires by insert molding are drawnoutside.

Since the bus bars, voltage detection terminals, connecting electricwires and the like are formed by insert molding through two steps;namely, the primary molding with respect to the plate harness and thesecond molding including the superposed connection of the bus bar andthe voltage detection terminal, dimensional control over the shrinkageof molded resin plate can readily be effected.

A low-cost connecting plate is producible as it is capable of usingordinary electric wires covered with polyvinyl chloride or polyethylenein place of special heat-resistant electric wires covered with polyimideresin.

Moreover, dimensional control over the whole connecting plate isfacilitated since the partial exposed portions of electric wires can beutilized for dimensional adjustment due to shrinkage of resin and thelike.

While there has been described in connection with the preferredembodiment of the invention, it will be obvious to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the invention, and it is aimed, therefore, to cover inthe appended claim all such changes and modifications as fall within thetrue spirit and scope of the invention.

What is claimed is:
 1. A connecting plate for a battery holdercomprising: a plurality of bus bars each for connecting a plurality ofbatteries; a molded resin plate in which said plurality of bus bars areintegrally molded at intervals corresponding to an arrangement of theplurality of batteries installed in said battery holder; and voltagedetection terminal incorporated in said molded resin plate for detectingvoltage of a desired one of said batteries in such a condition as to beconnected to the bus bars; wherein the voltage detection terminal has asuperposed contact portion at one end with respect to the bus bar, anelectric-wire connecting portion at the other, and a device mountingportion for mounting a circuit protective element at an middle positionbetween the one and other ends thereof, the other end of the electricwire whose one end is connected to said electric-wire connecting portionis led out from the molded resin plate, and the circuit protectiveelement is connected to the device mounting portion.
 2. A connectingplate for a battery holder as claimed in claim 1, wherein the moldedresin plate is provided with an electric wire holder integrally formedwith one side edge of the molded resin plate; and the other end side ofthe electric wire whose one end is connected to the voltage detectionterminal is held by the electric wire holder.
 3. A connecting plate fora battery holder as claimed in claim 1, wherein the molded resin-plateis provided with a pair of upper and lower elastic mats integrallymolded to one side edge of the molded resin plate; and the other endside of the electric wire whose one end is connected to the voltagedetection terminal is held by the mats.
 4. A connecting plate for abattery holder as claimed in any one of claims 1-3, wherein the moldedresin plate has a mounting window vertically opened so that the devicemounting portion of the voltage detection terminal is exposed from theconnecting plate; and the voltage detection terminal is contained in themounting window.
 5. A connecting plate for a battery holder as claimedin claim 4, wherein the device mounting portion of the voltage detectionterminal comprises a connecting piece for integrally holding thesuperposed contact portion and the electric-wire connecting portion; andthe connecting piece is cut off in the mounting window, the circuitprotective element being connected between the superposed contactportion and the electric-wire connecting portion.
 6. A connecting platefor a battery holder as claimed in claim 4, wherein a window frame formounting the circuit protective element is formed by providing a wallwhich surrounds the mounting window of the molded resin plate; and apair of element fixing arms are provided within said window frame.
 7. Aconnecting plate for a battery holder as claimed in claim 5, wherein awindow frame for mounting the circuit protective element is formed byproviding a wall which surrounds the mounting window of the molded resinplate; and a pair of element fixing arms are provided within said windowframe.